Apparatus for making pull-tab type closures and method



Jan. 24, 1961 D. R. JONES 2,969,105

' APPARATUS FOR MAKING PULL-TAB TYPE CLOSURES AND METHOD Filed Jan. 3, 1958 2 Sheets-Sheet l .w @INN Jan. 24, 1961 D. R. JONES 2,969,105

APPARATUS FOR MAKING PULL-TAB TYPE CLOSURES AND METHOD Filed Jan. 5, 1958 2 Sheets-Sheet 2 nited State APPARATUS FOR MAKING PULL-TAB TYPE CLOSURES AND METHOD Filed Jan. 3, 1958, Ser. No. 707,021

9 Claims. (Cl. 154-1.6)

v This invention relates to the manufacture of pull tabs from a continuous strip of tab forming material and applying and fastening the same to closure disks of the type used in packaging units wherein the rim portion of the receptacle to be closed by one of said closure disks is folded or pressed down or rolled upon the rim of the closure disk to retain the cover against unintentional removal from the receptacle.

More particularly, the present invention contemplates the manufacture of a closure disk with a pull tab wherein the tab is in the form of a strip fastened by an adhesive joint to the side of the closure ultimately facing the contents of the package and is extended around an edge portion of closure to provide an end portion outside the confines o-f the package for engagement by the lingers of the user to pull the closure out of the receptacle when access to the contents is desired.

It is an object of this invention to provide apparatus for the production of closure disks with pull tabs, as indicated, which includes mechanism for simultaneously advancing in juxtaposed relation along a given path a continuous strip of tab forming material and a row of closure disks.

The invention has as a further object the provision of apparatus as indicated including mechanism for fastening the strip to the closure disk in two stages wherein a portion of the tab is applied and fastened to one side of the closure in the first stage and a second portion of the tab is applied and fastened to the opposite side of the closure in the second stage.

Another object resides in providing apparatus as indicated in which the tab is severed from the strip between a first stage of operation wherein a portion of the tab is fastened to one side of the closure and a second stage of operation wherein a second portion of the tab is fastened to the opposite side of the closure.

These and other specific objects and advantages of the invention will be apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing, in which:

Fig. 1 is a diagrammatic side view of a typical apparatus adapted to perform the successive steps o-f applying a pull tab on a closure disk in accordance with the present invention, parts being shown in section to better distinguish them from adjacent parts.

Fig. 2 is a top plan view thereof.

Figs. 3, 4 and 5 illustrate the various steps in the pror duction of a closure and pull tab assembly according to the present invention.

Fig. 6 is an enlarged top perspective view of the final product.

In carrying out the manufacture of a closure and closure pull tab unit in accordance with the present invention, an installation substantially as shown diagrammatically in the drawing may be utilized to rapidly and eectively produce successive completed units. Referring particularly to Figs. 1 and 2 of the drawing, the tab forming material in the form of .a relatively thin and ice flexible strip 10 of stock (such as a synthetic resin tape marketed under the trademark Mylar) may be supplied in the desired quantity from a rotatably supported roll 11. The free end of the strip 10 may be withdrawn from the roll 11 by a set of draw rolls 12 or the like. The strip 10 is thus advanced along a path in superposed aligned relation to the operative upper run of an endless conveyor generally indicated at 13. The conveyor includes a pair of horizontally spaced parallel shafts 14 having sprocket wheels 15 mounted on opposite ends thereof. A pair of transversely spaced chains 16 are trained about the sprocket wheels 15. Extending between the chains 16 is a series of holders 17 having their opposite ends suitably secured to corresponding links of the chains. Each holder 17 is recessed to form a pocket accommodating an individual closure disk 18. As the conveyor is operated in a clockwise direction as viewed in Fig. 1, the holders 17 are successively brought into a position opposite the discharge end of a magazine 19 in which a desired quantity of closure disks are arranged in stacked relation. It will be noted that the holder 17 in registry with the magazine 19 as shown in Fig. 1 has travelled only a relative-ly sho-rt distance from the beginning of the upper operative run of the conveyor. The closure disks 18 -are successively withdrawn from the bottom of the magazine 19 and deposited in the pocket of the holder 17 in registry with the magazine by any suitable mechanism. Thus each closure disk 18 after being brought into seated position on its associated holder 17 is thereafter carried along the upper run of the conveyor until said holder 17 reaches the end of the upper run of the conveyor, at which position the closure disk 18 is dumped in a suitable collecting device (not shown). While thus carried along the upper run of the conveyor, a portion of the strip 10 is brought into engagement with the upwardly disposed face of the closure disk 18 u-nder pressure applied by a shoe 20 carried by a roller 21 supported for rotation about an axis transverse of the path of the conveyor. As shown in Fig. 1, four such shoes 20 are arranged in spaced apart relation circumferentially of the roller 21. r[he advancement of the strip and conveyor and the roller 21 are operated in timed relation so as to cause the shoes 20 to be successively moved into engagement with selected areas of the strip 10 moving continuously below with the leading end of each area substantially coincident with the leading edge of the closure disk opposite said roller 21. The length of each shoe 20 measured peripherally of the roller is limited to a distance slightly exceeding half the dimension of the closure disk. The surface of the strip facing the closure disk ultimately attached thereto is preferably coated with an adhesive capable of forming a bond with closure disk with the aid of heat and pressure. Each shoe 20 is therefore preferably heated by a suitable heating element and by means of spaced apart projections 20a on each of said shoes 20 operative to form indentations in the area of the strip 10 acted upon by said shoes, said area of the strip 10 is joined to the face of the closure disk opposite thereto by plasticizing of the adhesive coating of the strip at only such intervals of indentation which thereby produces a fastening between said face of thev closure and said area of the strip which may be readily and easily unfastened when desired.

After the closure disk moves forwardly to a position free of the roller 21, the strip 10 is enhgaged by a cutter along a line cro-sswise of the strip and rearwardly of the center of the disk but short of the trailing edge of the disk. The cutter, as shown in Fig. 1, includes a rotary member 22 having its axis of rotation transverse to the path of the conveyor and provided with a series of four heated blades or wires 23 spaced apart circumferentiallly of the member 22 and parallel to said axis of rotation 0f the member 22. By operation of the rotary member 22 in timed relation to the conveyor, the heated blades 23 are caused to be successively moved into engagement with selected portions of the strip moving continuously below, with each Vinterval of engagement taking place slightly rearwardly of the center of the disk opposite the cutter. In this manner the unfastened area of the severed strip app-lied to each disk forms an extension of the fastened area in -leading relation to the leading edge of the disk. As the disk moves forwardly to a position free of the cutter, the unfastened portion of the severed strip applied to said disk is engaged by a tucker supported for about an axis transverse to the path of the conveyor. The tucker, as shown in Fig. l, includes a hub portion having four spoke like arms 25 spaced at 90 deg ees apart. Through operation of the tucker in timed relation to the conveyor, the arrns Z5 are caused to be successively moved into engagement with the leading unfastened end portion of the severed strip travelling thereunder to depress said end portion into a downwardly hanging position in front of the leading edge of the disk. A stationary bridge 26 straddling the path of the upper run of the conveyor with which the fastened portion of the strip on said closure disk has upward wiping engagement effective to prevent accidental lifting of said portion as the downwardly bent unfastened portion of the strip approaches a second bridge member 27 facing the lower face of said disk as it moves forwardly on the upper run of the conveyor. The downwardly bent unfastened portion of the strip is engaged by the second bridge member 27 to cause said unfastened portion to be wiped progressively rearwardly of the leading edge of the disk to position said unfastened portion of the strip against the lower face of the disk. The unfastened strip portion is thereby prepared for engagement by a second roller unit having four heated shoes 28. As shown in Fig. l, the second roller unit is mounted for clockwise rotation about an axis parallel to the axis of rotation of the sprocket wheels of the conveyor and its opeartion is in such timed relation to the travel of the conveyor as to cause said shoes 28 to be successively presented for engagement with the portion of the strip facing the lower face of the disk. While so presented to the strip, heat and pressure is applied to the portion of the strip engaged thereto to plasticize the adhesive coating on the strip and thereby fasten the same to the lower face of the disk opposite thereto. The shoes Z8 are preferably smooth so as to produce a bonding of the strip and the lower face of the closure disk opposite thereto throughout the area of said face ofthe disk overlapped by said strip.

The conveyor while moving about the sprocket into a downwardly inclined position preparatory to commencing travel along the ylower run thereof allows the disk, after leaving a position opposite the second roller unit, to fall by gravity for discharge to a suitable collecting station.

As shown in Figure 2, holders 17 are essentially U- shaped bodies with legs 42 of a trailing body ih pivotally connected, as at 44, to lugs 46 o-f the neXt adjacent leading body di). The closure disc t8 carried by each holder 17 rests on U-shaped ridge 48 formed about the inside surface 50 of body iii which defines the space 52 that the disc carried by each holder 17 extends across.

From the foregoing description, it is apparent that the present invention provides an improved packaging unit in the form of a closure disk with a closure tab by means of apparatus and method of manufacture assuring a maximum rate of production at a minimum cost.

It should be understood that it is not desired to limit this invention to Vthe exact steps of the method or to the precise details of construction of the apparatus shown and described, since various modifications within the scope of the appended claims may occur to persons skilled in the art to which this invention pertains 'and it is also cohtemplated that the specific descriptive terms used herein be given the broadest possible interpretation consistent with the disclosure.

What is claimed is:

l. The method of producing closure disks with a pull tab, wherein said tab is initially provided with a coating of adhesive capable of being bonded to the surface of the closure disk by application of heat and pressure, which method comprises advancing a row of closure disks and a continuous strip of tab forming material along adjacent paths at the same speed, with the coated side of said strip and said disks in'face to face relation, applying heat and pressure to said strip at successive intervals along areas spaced apart lengthwise of said strip -coincident with opposite areas of the disk faces extending inwardly from the leading edge of said disks a distance short of the trailing edge of said disks, subsequently severing said fastened portion of the strip from the portion of the strip in trailing relation to said fastened portion along a line forward of the trailing edge of said disk, bending the portion of the strip extending forwardly of the leading edge of the disk into a position around the leading edge of the disk and underlying the lower surface of the disk and thereafter applying heat and pressure to said latter portion of the strip to fasten the same to the lower surface of the disk.

2. In apparatus for producing a closure disk having a pull tab wherein said pull tab is initially in the form of a continuous strip of relatively thin material having a coating capable of forming an adhesive joint with said disk with the aid of heat and pressure, the combination of means for conveying a plurality of said disks in single tile in upwardly facing relation along a given path and simultaneously advancing said strip in superposed relation to the disks carried by said conveyor with the coated surface of said strip facing said disks, heat and pressure means with which said strip is engageable to attach a selected portion of said strip to an area of the upper face of the disk opposite thereto and extending rearwardly from the leading edge of the disk a distance short of the trailing edge of the disk, a cutter with which said strip is subsequently engageable to sever said selected portion of the strip from the portion of the strip in trailing relation thereto along a line substantially coincident with the rearward limits of said selected portion, and folding means with which the portion of the strip in leading relation to said selected portion is subsequently engageable to fold said leading portion against the lowei face of the disk, and a second heat and pressure applying device with which said folded portion of the strip is subsequently engageable to attach said folded portion to the area of the second face of the disk opposite thereto.

3. In apparatus according to claim 2 wherein said heat and pressure means with which said strip is rst engageable includes a roller means rotatable about an axis transverse to the path of the strip and having a plurality of heated shoes thereon arranged in uniformly spaced apart relation peripherally of said roller, said roller being driven at a speed to present said shoes successively to said strip at intervals corresponding to the successive arrival of said disks at a position opposite said roller.

4. In apparatus according to claim 3 wherein each of said heated shoes is provided with radially offset portions eiective to indent selected portions of the area of the strip facing the upper face of the disk opposite thereto.

5. In apparatus according to claim 3 wherein said heat and pressure means with which said strip is finally engageable vincludes a roller means rotatable about an axis transverse to the path of the strip and facing the lower face of the disk opposite thereto, and said latter roller means having a plurality of heated shoes thereon arranged .uniformly spaced apart relation `nerr-irllerally of said roller, said latter roller being driven at a speed to present said shoes successively to said strip at intervals corresponding to the successive arrival of said disks at a position opposite said roller.

6. In apparatus according to claim 2, wherein said cutter includes a plurality of heated cutting blades supported for rotation about an axis transverse to the path of the strip and arranged in uniformly spaced apart relation circumferentially of said axis, said cutter being driven at a speed to present said cutting blades successively to said strip at intervals corresponding to the successive arrival of said disks at a position opposite said cutter.

7. In apparatus according to claim 2, wherein said folding means includes a plurality of arms radiating from a hub portion supported for rotation about an axis transverse to the path of the strip and arranged in uniformly spaced apart relation circumferentially of said axis, said cutter being driven at a speed to present said arms successively to said strip at intervals corresponding to the successive arrival of said disks at a position in predetermined relation to said folding means.

8. The method of applying a pull tab to a container closure disc, which method includes the steps of advancing a row of closure discs and a continuous tab forming strip in superposed similarly directed paths, successively bonding said strip to the surface of each disc in said row that faces said strip at a selected area spaced forwardly of the trailing edge of each disc, successively severing the strip at each disc at the portion of the strip that extends between the strip portion bonded by the last mentioned step and a point spaced from the leading edge of the next trailing disc, whereby each disc is successively provided with a strip segment that extends forwardly of each disc, successively bending said strip segments of said discs along the leading edge of the disc and into engagement with the other surface of the disc, and bonding said strip segment to said other surface of each disc.

9. Apparatus for applying pull tabs to container covers, said pull tabs being formed from a strip of material having a heat and pressure sensitive adhesive applied to `one surface thereof, said apparatus comprising means for conveying a row of said covers in single file and said strip of pull tab forming material in superposed paths extending in substantially the same direction, with said row of covers being positioned opposite said one surface of said strip, heated shoe means for successively pressing said one surface of said strip against one surface of the individual covers to elect a bond between said strip and said covers of said row, said shoe means being positioned to contact said strip between the leading edge of each cover and a point short of the trailing edge thereof, means for severing said strip between said point of each cover and the leading edge of the following cover, whereby each cover is provided with a strip segment that extends forwardly of the cover, means for folding the individual strip segments into engagement with the other surface of the individual covers, and means for bonding said strip segments to said other surface of the individual covers.

References Cited in the tile of this patent UNITED STATES PATENTS 2,334,381 Bronander Nov. 16, 1943 2,388,770 Stein Nov. 13, 1945 2,630,046 Raynolds Mar. 3, 1953 2,715,861 Jacobsen Aug. 23, 1955 

